1H-MRS imaging in intractable frontal lobe epilepsies characterized by depth electrode recording.

Abstract

Presurgical evaluation of frontal lobe epilepsy (FLE) remains a challenging issue and frequently requires invasive depth electrode recording. In this study, we aimed at evaluating the potential usefulness of a non-invasive technique such as proton magnetic resonance spectroscopic imaging ((1)H-MRSI) in the presurgical evaluation of FLE and at investigating the potential electrophysiological correlates of the metabolic disturbances as defined by (1)H-MRSI. We compared the distribution of (1)H-MRSI abnormalities with the electrophysiological abnormalities defined by stereo-electroencephalography (SEEG) recording in 12 patients presenting with several subtypes of FLE. We also used 12 control subjects in order to obtain normative (1)H-MRSI data. We used a multilevel (1)H-MRSI protocol to better sample the principal regions of the frontal lobe. We also applied a metabolic mapping technique allowing a visual display of metabolic data. A significant decrease of both N-acetyl-aspartate/phosphocreatine-creatine and N-acetyl-aspartate/(choline-compounds + phosphocreatine-creatine) ratios was observed in regions involved in the epileptogenic zone (EZ) and/or the irritative zone (IZ) compared to regions without electrical abnormalities in the same patients (P = 0.044 and P = 0.018, respectively), and also compared to controls (P = 0.004 and P = 0.0001, respectively). No significant differences in metabolic ratios were observed between those regions involved in the EZ and those involved in the IZ only. Our results suggest a link between the relative decrease of N-acetyl-aspartate and the EZ as well as the IZ in FLE. Thus, multilevel (1)H-MRSI protocol may add pertinent information during the non-invasive presurgical evaluation of FLE.

• Authors: M Guye, J P Ranjeva, Y Le Fur, F Bartolomei, S Confort-Gouny, J Regis, P Chauvel, P J Cozzone
• Journal: NeuroImage (Neuroimage) Vol. 26 Issue 4 Pg. 1174-83 (Jul 15 2005) ISSN: 1053-8119 [Print] United States
• PMID: 15878676 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Phosphocreatine
• Aspartic Acid
• N-acetylaspartate
• Creatine
• Choline

Topics

• Adolescent
• Adult
• Aspartic Acid (analogs & derivatives, metabolism)
• Brain Mapping
• Choline (metabolism)
• Creatine (metabolism)
• Drug Resistance
• Electrodes
• Electroencephalography
• Electrophysiology
• Epilepsy, Frontal Lobe (metabolism, pathology, physiopathology)
• Female
• Frontal Lobe (metabolism, pathology, physiopathology)
• Humans
• Magnetic Resonance Imaging
• Male
• Phosphocreatine (metabolism)